The invention relates to a manually operated implement or tool, in particular hedge shears, a brush cutter or similar device.
Manually operated tools having an internal combustion engine as the drive engine have, in their drive trains, a centrifugal clutch which is engaged and produces a positive connection between the internal combustion engine and the tool to be driven above a predetermined limit speed. When the internal combustion engine is at idle, the clutch disengages the tool from the drive engine.
On the engine side, the centrifugal clutch has a clutch support which is fixed to a drive part driven by the internal combustion engine and on which is guided at least one centrifugally actuatable clutch body. A drive part to be driven by the internal combustion engine and from which the flow of power runs to the tool to be driven comprises a clutch housing which overlaps the clutch support with the clutch body. The clutch bodies run on the rotationally mounted drive part with the clutch support in such a manner that they can be moved radially outwards against a spring force. When the limit speed is reached, the clutch bodies are forced radially outwardly until their insides come into contact with a peripheral wall of the clutch drum, at which point friction causes a positive connection between the drive part and the power take-off part.
Certain models of manually operated tools are designed such that the power take-off part is mounted in a separate power take-off housing, the internal combustion engine being fastened to the power take-off housing. In such cases, the drive part is mounted on the engine side and generally fastened directly to the crankshaft of the internal combustion engine. Assembly takes place in several stages. First, the engine assembly and the drive part and the power take-off housing and the power-take off part are assembled separately. The engine assembly is then fixed to the power take-off housing. Alignment pins which project with play into corresponding openings are provided to ensure accurate alignment during final assembly. This ensures the accurate alignment of the engine and drive part in relation to the power take-off housing and power take-off part.
Undesirable vibrations and rough engagement and disengagement sometimes referred to as “clutch grabbing” can be observed in tools of this design. Costly of such measures can at least be reduced.
It is therefore an object of the present invention to design a tool of the aforementioned general type in such a manner that it runs more quietly.